5764-66-9Relevant academic research and scientific papers
Photochemistry of group 14 1,1,1-trimethyl-2,2,2-triphenyldimetallanes (Ph3MM′Me3; M, M′ = Si, Ge). Direct detection and characterization of silene and germene reactive intermediates
Leigh, William J.,Toltl, Nicholas P.,Apodaca, Paula,Castruita, Madeli,Pannell, Keith H.
, p. 3232 - 3241 (2008/10/08)
The photochemistry of trimethylsilyltriphenylgermane (Ph3GeSiMe3), triphenylsilyltrimethylgermane (Ph3SiGeMe3), and 1,1,1-trimethyl-2,2,2-triphenyldigermane (Ph3GeGeMe3) has been studied in hydrocarbon solution by steady state and laser flash photolysis methods and is compared to previously reported data for the homologous disilane Ph3SiSiMe3. A variety of products are formed upon photolysis of the three compounds in the presence of 2,3-dimethyl-1,3-butadiene or chloroform, but in each case the major ones are derived from M-M′ bond homolysis and dimethyl- or diphenylgermylene extrusion. The trapping products of the 1,3,5-(1-metalla)hexatriene derivatives formed by [1,3]-MMe3 migration into the ortho-position of one of the phenyl rings are formed as well, in yields of 9-30%. While these experiments indicate that germylenes are formed in at least twice the yield of the 1,3,5-(1-metalla)hexatrienes, only the latter and triphenylsilyl or triphenylgermyl radicals can be detected by laser flash photolysis techniques. The metallaenes have been identified on the basis of their time-resolved UV absorption spectra and absolute rate constants for reaction with 2,3-dimethylbutadiene, methanol, acetone, acetic acid, oxygen, and carbon tetrachloride and can be distinguished from germylenes by their lack of reactivity toward triethylsilane and chloroform. Radical formation is shown to result from reaction of the triplet states of these compounds, and a triplet lifetime is estimated for Ph3GeSiMe3 and compared to that of the disilane homologue. The results of time-resolved experiments on other, related compounds are discussed in light of these results.
Photochemical reactions of aryl-substituted catenates of group 4B elements, PhMe2E-E'Me3 (E, E' = Si and Ge). Formation of a radical pair
Mochida, Kunio,Kikkawa, Haruhiko,Nakadaira, Yasuhiro
, p. 9 - 19 (2007/10/02)
Photochemical reactions of phenyl substituted catenates of group 4B elements, PhMe2E-E'Me3 (E, E' = Si and Ge) have been investigated by chemical trapping experiments and laser flash-photolysis.On irradiation, the phenylated group 4B catenate undergoes E-E' bond homolysis to give a pair of radicals (PhMe2E. and Me3E'.).In CCl4, these radicals are converted to the corresponding chlorides by abstraction of a chlorine atom.In a nonhalogenated solvent, the radical pair couples at the ipso-position of the phenyl group of the pairing radical (PhMe2E.) to yield the cor responding diradical.This undergoes either elimination of a divalent species (Me2E:) with concomitant formation of trimethylphenyl group 4B element PhMe3E') or intramolecular 1,2-group 4B element migration to yield group 4B metal-carbon double bonded species.The radical escapes from the solvent cage coupled to the metal atom of the radical to yield the dimetallic product.The reaction path observed is highly dependent on the nature of the group 4B element comprising the phenyl substituted catenate.
Photochemical Reactions of Vinyl-, Styryl- and Benzyl-Substituted Digermanes
Mochida, Kunio,Kikkawa, Haruhiko,Nakadaira, Yasuhiro
, p. 2772 - 2777 (2007/10/02)
Photochemical reactions of vinyl-, styryl- and benzyl-substituted digermanes by chemical trapping experiments.Photolysis of vinylpentamethyldigermane afforded 1-trimethyl-2-(pentamethyldigermyl)ethane as a major product, and styrylpentamethyldigermanes gave mainly styryltrimethylgermane.On the other hand, photolysis of benzyl-substituted digermanes (benzylpentamethyldigermane and 1,2-dibenzyltetramethyldigermane) gave hydrogermanes and hydrodigermanes as main products, respectively.These products were derived from germyl radicals generated by photoinduced homolysis of the germanium-germanium bond.In carbon tetra chloride (CCl4), these germyl radicals were converted to the corresponding chlorogermanes by abstraction of a chlorine atom.Germylene species were also to be evolved from such photolyses.
New photochemical routes to germylenes and germenes and kinetic evidence concerning the germylene-diene addition mechanism
Bobbitt, Kevin L.,Maloney, Vincent M.,Gaspar, Peter P.
, p. 2772 - 2777 (2008/10/08)
Upon 254-nm irradiation of phenylbis(trimethylsilyl)germanes, there is competition between two germylene-forming reactions, the unexpected elimination of phenyltrimethylsilane and the elimination of hexamethyldisilane. Irradiation of a phenylmonosilylgermane PhGeMe2SiMe3 leads to predominant elimination of PhSiMe3, forming dimethylgermylene Me2Ge:, accompanied by migration of Me3Si to the ortho position of the phenyl ring, forming a germene. Laser flash photolysis of PhGeMe2SiMe3 is a convenient source of Me3Ge:, and rate constants are reported for Me2Ge: addition to a series of dienes and other substrates. The kinetic data are in accord with 1,2-addition as the dominant pathway for addition of Me2Ge: to 1,3-dienes.
Photochemistry of aryl-substituted trigermanes. Generation and mechanism of formation of germylenes
Mochida, Kunio,Yoneda, Isao,Wakasa, Masanobu
, p. 53 - 62 (2007/10/02)
Photochemical reactions of aryl-substituted trigermanes have studied by trapping experiments, matrix isolation, and laser flash-photolysis techniques.Photolysis of the phenylated trigermanes involved both the simple extrusion of germylenes and the formati
Electronic absorption spectra of diorganogermylenes in matrices: Formation of diorganogermylene complexes with heteroatom-containing substrates
Ando, Wataru,Itoh, Hiroyuki,Tsumuraya, Takeshi
, p. 2759 - 2766 (2008/10/08)
Diorganogermylenes were generated in hydrocarbon matrices at 77 K by the photolysis of 7-germanorbornadienes 1a-e or bis(trimethylsilyl)germanes 2a-g. The germylenes show electronic absorption bands at 420-558 nm. The germylenes react with heteroatom-containing substrates (R2O, R2S, R3P, R3N, RCl, and ROH) to form adducts, which show characteristic absorption bands at shorter wavelengths than those of germylenes.
Photochemistry of aryl-substituted trigermanes
Wakasa, Masanobu,Yoneda, Isao,Mochida, Kunio
, p. C1 - C5 (2007/10/02)
The photolysis of phenyl-substituted trigermanes affords digermanes and germenylenes.Trapping experiments, matrix isolation, and laser-photolysis studies indicate that the photoreaction of these compounds involves both the extrusion of germylenes and the
Laser photolysis of aryl-substituted digermanes. Generation of germyl radicals and germylenes
Mochida, Kunio,Wakasa, Masanobu,Nakadaira, Yasuhiro,Sakaguchi, Yoshio,Hayashi, Hisaharu
, p. 1869 - 1871 (2008/10/08)
Laser flash photolysis of the phenyl-substituted digermanes (PhnMe3-nGe)2 results in Ge-Ge bond homolysis to give germyl radicals and probably a germylene.
